Hole doping of MgB2C2, a MgB2 related [B/C] layered compound

The MgB2 related borocarbide MgB2C2 was synthesized and various attempts were made to hole dope the material. MgB2C2 is orthorhombic (space group Cmca a=10.92 Å, b=9.45 Å, c=7.45 Å) with [B/C] nets. Successful synthesis was carried out from pure elements by a solid state reaction method in a closed environment. Theoretical calculations indicate the possibility of hole doping of MgB2C2 to be favorable for superconductivity due to the flat band (in the T–Y direction) similar to one in MgB2. Hole doping of MgB2C2 was attempted by two routes: (1) substitutional dope of Mg with alkali metals, (2) doping in the [B/C] nets, and as a result Li doping was indicated to be feasible with a possible semiconductor to metal transition induced. High pressure synthesis of (Mg,Li)B2C2 was also attempted but only resulted in formation of the LiBC phase.